AUG 10 1954
Animal Husbandry Mimeograph July, 1995
Series No. 54-5
UNIVERSITY OF FLORIIA
AGRICULTURAL EXPLRflENT STATION
WILLARD M. FIFIELL, Director
A COMPARISON OF CILOROTETRACYLIfTE
(AUREOMYCIN) PNE TETRACYCLINE
(ACHROIYClIN) AS GROWTH_ STIMU-
LANTS FOR THE PIG1
H. D. Wallace, F. A. NcMillan and J. McKigney
Department of Animal Husbandry and Nutrition
Several antibiotics have been shown to improve the growth rate of
young swine (2). Chlorotetracyline is one of the most effective. Tetra-
cyline has hot been throughly tested in this respect. It represents the
basic chemical structure in the antibiotic series which includes chloro-
tetracycline and oxytetra cycline (Terramycin). Tetracycline appears
to have a wide bacterial spectrum as do its two analogues; however, pre-
liminary investigations in human therapy have indicated a lower inci-
1. This work was supported in part by a grant from Lederle Laboratories,
Pearl River, New York.
2. Wallace, Associate Animal Husbandman, Agricultural Experiment Sta-
tion, McMillan and McKigney, Graduate Assistants, Department of Ani-
mal Husbandry and Nutrition. The technical assistance of W. E.
Collins, C. E. Haines, and L. Gillespie is gratifully acknowledged.
dence of nausea, vomiting and diarrhea with tetracycline than has been
observed with either chlorotetrocycline or oxytetracycline (1). In
view of these observations with the human it seemed worthwhile to evalu-
ate the compound as an ingredient for swine rations.
The purpose of this experiment was to compare the growth promoting
value of crude aureomycin (90 percent crystalline aureomycin-HCl), auro-
fac 2-A (a supplement containing 3,6 grams of aureomycin-HC1 per pound
with citrus meal as the carrier material), and tetracycline-HCl.
Thirty two pigs averaging about 85 pounds initially were divided
into four experimental groups according to weight, breed, litter and pre-
vious dietary history. The animals consisted of purebred Durocs, pure-
bred Hampshires, and Spotted Poland Chine x Duroc crossbreds. They
had been raised at the University Swine farm and were in good thrifty
condition at the start of the test. The pigs had been fed on concrete
pens since weaning at 56 days of age. Each lot of eight pigs was al-
lowed a 1/6 acre plot of oats and sweet yellow lupine pasture. The
pasture had previously been grazed heavily and was quite short at the
start of the test. At no time during the experiment was there abun-
dant forage available. However, by the conclusion of the test the pas-
ture was beginning to get ahead of the pigs indicating that they had
not been restricted in this respect. The pigs were fed by means of
self feeders and water was provided in automatic waterers.
The basal ration consisted of the following ingredients and con-
tained l4.5 percent crude protein.
Ground Yellow Corn 82.0
Soybean Oilmeal 16,0
Ground Limestone 1.0
Steamed Bonemeal 0.5
Salt-Trace Mineral 0.53
The salt-trace mineral mixture was composed of 50 Ibs. iodized salt, 921
gi. MnSO0, 398 gm. FeSO, 125 gm. CuSO4, and 10 gm. C0003. Lederle Forta-
feed 2-49C was added at a level of two lbs, per ton of feed. The Forta-
feed contained not less than 2000 mg, of riboflavin, 4000 mg. of panto-
thenic acid, 9000 mg. of niacin, 10,000 mg, of choline chloride and 60. ig.
of folic acid per pound. The antibiotic supplements were added on an
antibiotic equivalent basis which provided 10 gm. of antibiotic per ton
of feed in each of lots 2, 3 and .4
The experiment was initiated on January 26, 1954. The animals were
removed from the test individually as they reached a weight of approxi-
mately 195 pounds,
Results and Discussion
Results of the experiment are shown in Table 1. Analysis of the
growth data indicated no statistically significant differences. Never-
theless, all lots that received antibiotic performed some better than the
Table 1. The Effect of Chlorotetracycline and Tetracycline on the Growth of the Pig.
Baaal + Chloro-
Basal + Chloro-
Basal + Tetra-
Lot Number 1 2 3 4
No. of pigs
Av. Initial wt.
Av. Final wt.
Av. Gain per
Av. Daily feed
Feed per 100 lbs
Av. days on
;0ne pig died on the 27th
day with acute respiratory symptoms.
Exact cause was not
control group. The two lots which received chlorotetracyline out per-
formed, by a small margin, the lot which received tetracycline, This
difference could well have been due to chance alone, or to differences
in pasture consumption in the different lots. Antibiotic supplementation
improved feed efficiency considerably in all cases.
Thirty two pigs, weighing an average of 85 pounds initially, were
used to test the supplemental value of chlorotetracyline (2 sources) and
tetracycline. The experiment was conducted on oats-sweet lupine pasture
where total pasture intake could not be measured or controlled)under these
conditions, antibiotics did not significantly influence the rate of gain
but did improve feed efficiency.
Under the conditions of this trial there was no evidence obtained
which indicated tetracycline to be superior to chlorotetracyline as a
feed ingredient for growing-fattening swine.
1. Welch, H. 1954. Editorial An Appraisal of Tetracycline. Anti-
biotics and Chemotherapy 4: 375-379.
2. Braude, R., H. D. Wallace and T. J. Cunha, 1953. The Value of Anti-
biotics in the Nutrition of Swine: A Review. Antibiotics and Chemo-
therapy 3: 271w291.